1. Field of the Invention
The present invention relates to an image forming apparatus which includes exposure units each disposed opposite to a corresponding photoconductor.
2. Description of Related Art
Among image forming apparatuses for forming an image on a recording sheet, the so-called tandem type image forming apparatus is known in the art (e.g., see patent documents 1-3 listed below) which typically includes exposure units arranged in tandem and each disposed above and opposite to a corresponding photoconductor. The exposure units may be LED heads, for example, which use light-emitting diodes (LEDs) as a light source for forming an electrostatic latent image on a photoconductor. Varieties of such image forming apparatus known in the art include, for example: type I (as disclosed in patent document 1) in which a frame on which cartridges each containing a photoconductor are supported is slid upward to render any of the cartridges replaceable; and type II (as disclosed in patent documents 2 and 3) in which cartridges each containing a photoconductor or a frame on which the cartridges are supported can be pulled out horizontally for replacement of the cartridges.